From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 2.6.13] lockless pagecache 2/7 From: Alan Cox In-Reply-To: <4318FF2B.6000805@yahoo.com.au> References: <4317F071.1070403@yahoo.com.au> <4317F0F9.1080602@yahoo.com.au> <4317F136.4040601@yahoo.com.au> <1125666486.30867.11.camel@localhost.localdomain> <4318C28A.5010000@yahoo.com.au> <1125705471.30867.40.camel@localhost.localdomain> <4318FF2B.6000805@yahoo.com.au> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Sat, 03 Sep 2005 18:31:36 +0100 Message-Id: <1125768697.14987.7.camel@localhost.localdomain> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andi Kleen , Linux Memory Management , linux-kernel List-ID: On Sad, 2005-09-03 at 11:40 +1000, Nick Piggin wrote: > We'll see how things go. I'm fairly sure that for my usage it will > be a win even if it is costly. It is replacing an atomic_inc_return, > and a read_lock/read_unlock pair. Make sure you bench both AMD and Intel - I'd expect it to be a big loss on AMD because the AMD stuff will perform atomic locked operations very efficiently if they are already exclusive on this CPU or a prefetch_w() on them was done 200+ clocks before. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org